Hi, Sorry for the delay... I was hoping to cherry-pick this and test against 4.9.x, but it didn't apply cleanly, although it looks trivial to do it by hand. Is it recommended/okay to test this patch against 4.9.x? Will the fix eventually be merged into 4.9.x? --Marc On Tue, Apr 4, 2017 at 11:01 PM, Guoqing Jiang <jgq516@xxxxxxxxx> wrote: > > > On 04/04/2017 10:06 PM, Marc Smith wrote: >> >> Hi, >> >> I encountered an oops this morning when stopping a MD array >> (md-cluster)... there were 4 md-cluster array started, and they were >> in the middle of a rebuild. I stopped the first one and then stopped >> the second one immediately after and got the oops, here is a >> transcript of what was on my terminal session: >> >> [root@brimstone-1b ~]# mdadm --stop /dev/md/array1 >> mdadm: stopped /dev/md/array1 >> [root@brimstone-1b ~]# mdadm --stop /dev/md/array2 >> >> Message from syslogd@brimstone-1b at Tue Apr 4 09:54:40 2017 ... >> brimstone-1b kernel: [649162.174685] BUG: unable to handle kernel NULL >> pointer dereference at 0000000000000098 >> >> Using Linux 4.9.13 and here is the output from the kernel messages: >> >> --snip-- >> [649158.014731] dlm: 5b3b8f94-7875-b323-5bb8-29fa6866f4a8: leaving the >> lockspace group... >> [649158.015233] dlm: 5b3b8f94-7875-b323-5bb8-29fa6866f4a8: group event >> done 0 0 >> [649158.015303] dlm: 5b3b8f94-7875-b323-5bb8-29fa6866f4a8: >> release_lockspace final free >> [649158.015331] md: unbind<nvme0n1p1> >> [649158.042540] md: export_rdev(nvme0n1p1) >> [649158.042546] md: unbind<nvme1n1p1> >> [649158.048501] md: export_rdev(nvme1n1p1) >> [649161.759022] md127: detected capacity change from 1000068874240 to 0 >> [649161.759025] md: md127 stopped. >> [649162.174685] BUG: unable to handle kernel NULL pointer dereference >> at 0000000000000098 >> [649162.174727] IP: [<ffffffff81868b40>] recv_daemon+0x1e9/0x373 > > > Looks like the recv_daemon is still running after stop array, commit > 48df498 "md: move bitmap_destroy to the beginning of __md_stop" > ensure it won't happen. > > > [snip] > >> Perhaps this is already fixed in later versions? Let me know if you >> need any additional information. > > > Could you pls try with the latest version? Please let me know if you > still see it, thanks. > > Regards, > Guoqing > -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html